1. Field of the Invention
The present invention relates generally to cooling systems. More particularly, the invention concerns an apparatus for cooling a heat producing member such as a computer chip or the like.
2. Discussion of the Prior Art
During operation integrated circuit devices, such as computers generate significant amounts of heat. In order to maintain optimal performance this heat must be continuously removed. If the heat is not continuously and efficiently removed, the device may over heat resulting in reduction of operating performance and possible catastrophic damage. In order to avoid over heating, thermal management devices must be used. Prior art thermal management devices typically comprise heat sinks, thermal interface materials, fans, chassis ventilation, and combinations thereof.
As computer technology advances toward faster speeds and higher performance, thermal management becomes increasingly important. Maintaining the proper thermal environment in the computer system is key to reliable, long-term system operation. Typically, thermal management devices such as heat sinks induce improved heat dissipation through the heat dissipating surface areas coupled with strategically directed air flow from a fan disposed proximate the heat dissipating surface area.
The conventional prior art heat sink is formed of a material such as aluminum that readily conducts heat. The heat sink is usually placed on top of and in contact with the integrated circuit device. Through this contact, heat generated by the integrated circuit is conducted into the heat sink and away from the integrated circuit. Typically the heat sink includes a plurality of cooling fins which function to increase the surface area of the heat sink and thus maximize the transfer of heat from the heat sink device into the surrounding air. In this manner the heat sink draws heat away from the integrated circuit and transfers the heat into the surrounding air. A heat sink and fan combination can deliver better thermal performance than a heat sink alone. Accordingly, in order to enhance the cooling capacity of the heat sink, an electrically powered fan is often mounted on the top of the heat sink. Exemplary of this type of heat sink device is that disclosed in U.S. Pat. No. 5, 794,685 issued to Dean. Another prior art patent that discloses the use of a fan to carry heat away from the central processing unit is U.S. Pat. No. 5,740,014 issued to Lin. Still another heat sink device having radial heat and air flow paths is disclosed in U.S. Pat. No. 5,794, 685 issued to Dean.
The present invention is directed to a novel heat sink device that provides a uniquely configured heat dissipating member that functions to efficiently transfer into the surrounding air heat generated by the integrated circuit device. Cooperating with the heat dissipating member is a novel multi-bladed fan assembly that is so constructed and arranged as to draw air past the heat dissipating member and into the interior of the specially configured blades of the fan assembly of the apparatus.
As will be better appreciated from the discussion that follows, the novel cooling apparatus of the present invention cools the heat producing member in several ways. First, the heat from the heat producing member, such as the computer chip, is radiated from the multiplicity of fins of the heat dissipating member outwardly toward a generally truncated, conically-shaped, apertured shroud that surrounds the heat dissipating member. Second, intake air is drawn through the multiplicity of apertures formed in the shroud by a novel rotary fan blade assembly. Air drawn through the shroud flows past the novel heat dissipating member to cool the member by convection and is then directed into the hollow hub of the rotary fan assembly. Connected to the hollow hub are sixteen uniquely configured hollow fan blades, each of which has an apertured trailing edge. The heated gases emerging from the small apertures provided in the trailing edge of each blade create a jet thrust action to the rotating assembly and expand rapidly to produce an additional cooling effect. The heated air radiated from the heat dissipating member is further cooled as it is drawn past the shroud by the fan blades and then around and about the exterior of each of the hollow blades. The heated air passes completely around the exterior, surface of each and every blade from the root of the blade to the extreme tip. This produces a temperature drop not only within the hollow blade, but around the blade and the hub assembly as well.